Summary The Custom Helicopters Ltd. Bell206L-3 helicopter (registration C-GCHG, serial number51508) was transporting a lineman to Tower63 on the Sheridan power line near Cranberry Portage, Manitoba. While hovering near the tower, the helicopter's skid gear became entangled in the uppermost cablespan. The helicopter struck the tower and crashed on the adjacent power line right-of-way. The helicopter was substantially damaged by impact forces and fire; the pilot and passenger both sustained fatal injuries. The accident occurred during daylight hours at 0903central daylight time. Ce rapport est galement disponible en franais. Other Factual Information On the day of the occurrence, C-GCHG departed the Manitoba Hydro yard at RossLake (near FlinFlon), dropped off two linemen at Tower142 (near Whitefish Lake), and then proceeded to Tower63, which is near Nisto Lake (see AppendixA). The Manitoba Hydro flight-following log indicated that C-GCHG departed Tower142 at approximately 0854 central daylight time.1 At 0903, the 230-volt power line circuit breaker (P58C) tripped, which was considered to have coincided with the helicopter striking the tower (number63) structure and causing an electrical short in the power line. The pilot held a valid Canadian commercial helicopter pilot licence and had accumulated approximately 1300hours of flight experience on the Bell206 helicopter type. He had not received any training specific to helicopter operations near power lines, nor was that type of training required. According to available information, he was fit and qualified to act as the pilot-in-command of C-GCHG on the day of the accident. A preliminary autopsy report indicated that the pilot died of injuries sustained during the initial impact sequence. At the time of the occurrence, the pilot was well rested and had not flown an excessive number of hours. The passenger was seated directly behind the pilot during the departure of the accident flight. After the accident, his body was found at the base of the tower structure approximately 40feet from the wreckage. The passenger's injuries were determined to have resulted from a fall. The nearest recorded weather at the time of the accident was for FlinFlon, 10nautical miles (nm) north of the accident site. The 0900 FlinFlon weather was as follows: wind 020true(T) at 6knots, visibility 15statute miles in light rain, overcast cloud at 1500feet above ground level. Weather conditions such as this would allow the helicopter to operate under visual flight rules (VFR).2 There was no rain at Tower142. Although the actual weather conditions at the accident site could not be determined, light rain would not have obscured the pilot's perception of his position or his view of the tower. At the time of the accident, C-GCHG was contracted to Manitoba Hydro for transporting power line maintenance personnel for repair and inspection purposes. Line maintenance personnel were not trained or required to perform work from the helicopter while airborne. The nature of the flying was such that linemen were dropped off at the nearest suitable landing site, from where they walked to the tower, climbed up to perform the required work, climbed down, and walked back to the helicopter. It was not the practice of the operator or of Manitoba Hydro personnel to conduct work on a line from the helicopter during such operations. Wreckage and Site Information The main portion of the fuselage was 40feet northeast of the tower and was almost entirely consumed by the post-crash fire. The burnt area surrounding the fuselage was conical in shape and quite localized. The helicopter skid gear had been caught up in the tower cross arm structure and remained there. The right skid gear had cable scratches on it that matched the pattern of the uppermost skyline cables.3 The skid gear attachment point had failed from tensional overload forces in the forward direction where it had separated from the belly of the fuselage. Both upright arms of the hydro tower were damaged and the westerly cable span was significantly stretched. The main rotor head and the blades separated from the fuselage and were found 100feet east-northeast of the tower. The rotor mast had failed due to torsional overload forces consistent with those sustained from a high-power, main rotor strike. The tail boom had been torn away from the main fuselage and was located approximately 60feet south of the main wreckage area. The first-stage engine compressor rotors showed indications of rubbing on the casing, a small visible collapse of the compressor blades on the left side, and a bending of the left-side inlet guide vane. There was rubbing on the blade tips of the last stage of the power turbine rotor. There was no indication of any pre-impact mechanical anomalies. C-GCHG was a commercially registered helicopter and a review of its technical records indicated that it been maintained in accordance with the Canadian Aviation Regulations (CARs). The gross weight of the helicopter could not be accurately determined; however, an estimated weight and balance calculation indicated that the helicopter's weight and centre of gravity were within limits at the time of the accident. A global positioning system (GPS) receiver found in the wreckage was sent to the TSB Engineering Laboratory. An examination of the data stored in the unit indicated that no flight track or route data for the flight from Tower142 to the accident site had been saved. Safety Oversight There are hazards associated with flying and hovering in a power line environment that are not associated with other helicopter operations.4 At the time of the occurrence, the helicopter operator did not offer or require any specialized training to identify and reduce exposure to these hazards. Large power utility companies and offshore oil exploration companies have a method of conducting safety audits on their contracted aviation companies. At the time of the occurrence, Manitoba Hydro did not have such a method of conducting safety audits on contract aviation companies.5 The most recent Transport Canada (TC) audit of the operator's flight operations took place in November2003. TC's audit schedule requires that Custom Helicopters Ltd. be audited every three years. The operator was not required to have a safety management system (SMS). Several of the management pilots gathered and communicated safety information throughout the company. However, there was no formal procedure for line pilots to report hazardous operations to management or any method of monitoring hazard identification and safety action. It was reported that some of the operator's pilots had been transferred off the Manitoba Hydro contract before the occurrence. It was believed that the reason for these transfers was that these pilots had refused to operate their helicopters under certain types of hazardous conditions. Some pilots had a perception of pressure to operate under hazardous conditions and to avoid reporting such conditions encountered while flying for Manitoba Hydro.